JP5371213B2 - Method for manufacturing flexible abrasive disc and flexible abrasive disc - Google Patents

Description

  The present invention relates to a method for manufacturing a flexible abrasive disc according to the premise of claim 1 of the claims.

  The invention also relates to a flexible abrasive disc as described in the preamble of claim 16 and manufactured by said method.

  It is known from the prior art to manufacture flexible abrasive means by coating a composite material, usually precisely formed in a pyramid shape, on a wide material strip. This method is described, for example, in US Pat. No. 5,152,917 (US Patent 5,152,917). In order to produce an abrasive disc by the method described above, the abrasive disc must be cut from the strip material. However, this requires precision die cutting tools. Since the strip of material is also coated with an abrasive, the blades of the punching tool are also significantly worn, which requires frequent replacement of the blades. This is expensive because both production is interrupted and both obtaining a new blade and installing it.

  The production of abrasive discs is also burdened by the large amount of waste generated during punching. This waste partly constitutes unused raw materials and partly needs to be removed from the production line and discarded or stored. Naturally, both of these factors negatively affect the cost of the abrasive disc.

  In the production of abrasive materials from wide strips of material, it is also almost impossible to use production methods that are technically advantageous. Such an advantageous method is, for example, using a vacuum treatment on the surface layer of the abrasive disc. The cost of generating a vacuum on a known type of material strip is too expensive to use this technique.

  Also, for example, according to US Pat. No. 2,292,261 (US patent 2,292,261) it is known from the prior art to coat individual abrasive discs with a slurry of binder and sand. Yes. This specification describes a method of coating a disk with a layer of an abrasive slurry having an accurate viscosity. Prior to curing, this layer is embossed using a structured plate. The desired pattern is formed in the slurry of the abrasive by embossing, and the slurry is then cured. In this method, the desired pattern is pressed very momentarily, so the result is not an exact duplicate, and the pattern tends to spread to some extent before it hardens, for example.

  According to the present invention, the problems of the known methods can be substantially eliminated. Thus, the present invention provides a method for producing a flexible abrasive disc, and a flexible abrasive disc produced by the method of the present invention, and as a result, an abrasive disc having stable production and uniform characteristics. Bring.

  The foregoing problems are solved by the present invention by providing the features of claims 1 and 16, respectively, for its manufacturing method and flexible abrasive disc. The subsequent dependent claims provide other suitable embodiments of the invention and variations of the embodiments that further improve its function.

  In the following description, terms such as “upper”, “lower”, “upper side”, “lower side” and the like refer to the abrasive disc and its structural details shown in the accompanying drawings. Is instructed.

  The method described in the present invention provides several significant advantages over the prior art. Therefore, since the size of the polishing disk is small, it is possible to manufacture an inexpensive mold by manufacturing the polishing disk one by one. The manufacturing technology of the present invention allows the use of disposable molds cast against positive originals. Handling of the abrasive disc after it has been finished with such a disposable mold is considerably easier. In addition, producing negative prototypes and then casting the required negative molds, as opposed to directly producing negative originals that are normally required when producing abrasive discs by conventional techniques. Is simpler and therefore also cheaper.

  Since one original mold can be used to manufacture a plurality of the above-mentioned disposable molds, even a very complicated mold can be made economically. This makes it possible to make the surface structure of the abrasive disc better than a normal one.

  In the production of the abrasive disc according to the invention, the abrasive disc is advantageously pressed in a press with upper and lower embossing pistons located opposite each other. Thereby, an embossing mold is advantageously provided on one embossing piston. By using an inexpensive disposable mold that can remain with the final product in the curing process, the mutual pressing operation is only very instantaneous in the method according to the invention. An abrasive coating applied to the backing of the abrasive disc holds the backing and the embossing mold together after the first press.

  Since each abrasive disc is formed between upper and lower embossing pistons and processed in a separate press chamber with a small volume, for example, it is easy to utilize known vacuum casting techniques. This technique allows for particularly precise casting and thus significantly improves the working characteristics of the abrasive disc.

  By protecting the abrasive coating of the abrasive disc with a disposable mold, it is possible to use not only UV curing but also e.g. electron beam curing. For example, electron beam curing is economically possible because it only requires a very small radiation source for beam curing.

  Abrasive discs produced by the method of the present invention and having a spherical cross section according to the present invention have better clogging properties in use. The sphere reduces what is called "caking", i.e. the accumulation of dust between the surface of the abrasive disc and the surface to be polished.

  In addition, thanks to the spherical shape, the entire abrasive surface of the abrasive disc can be used, not just the peripheral area of the disc normally used for most parts, thus extending the life of the abrasive disc. This is because the air does not stick to the flat surface, but air enters below the product that is bent to some extent. This increases the amount of air flow that is sucked outward, resulting in better dust removal. Beneficial results can be achieved even with abrasive disks having a large bending radius. The bending of the cross section of the abrasive disc may be, for example, only about 2 millimeters in a 150 millimeter abrasive disc so that an increased dust discharge effect can be seen.

  Since the spherical abrasive disc sticks in the same way as a conventional flat abrasive disc or is not pulled in various directions, the polishing operation carried out by the abrasive disc according to the invention is also facilitated. Furthermore, it is not necessary to hold the polishing machine firmly as in the past, or to direct it to the object, and even the middle part of the polishing disk can be used for easy polishing. Only the weights of the hands and arms themselves are needed.

  Spherical abrasive discs also reduce the polishing area and allow for a discrete transition between the polished and non-polished surfaces. This effect can be further enhanced by providing a substantially spherical shape on the fixed surface of the fixed plate of the polishing machine. In this way, even if the polishing machine is slightly inclined, the mutual geometric shapes of the contact surfaces located opposite to each other are not changed. Therefore, by imparting a spherical variation to the polishing machine, it is basically possible to eliminate the oblique tilt position of the polishing product disposed on the fixed surface of the polishing machine. Therefore, the polishing machine does not need to be precisely positioned in the polishing region as in the known method, and the operation by it is noticeably simpler.

  The spherical polishing surface allows a more discriminating and higher polishing pressure to be applied in the middle part of the contact surface of the polishing disk. In this way, this shape allows more accurate polishing or only specific defects in the current polishing area. Thanks to the present invention, the polishing area is reduced and the edge area around the polishing area is less noticeable.

  Further advantages and details of the invention will become apparent from the following description.

  The present invention will be described in detail below with reference to the accompanying drawings.

  A method for manufacturing a flexible abrasive disc and a preferred embodiment of such an abrasive disc will now be described with reference to the accompanying drawings. Such methods include the illustrated structural members, each indicated by a corresponding reference numeral. These reference numerals correspond to the reference numerals used in the following description.

  A flexible abrasive disc 1 according to the invention includes a backing 2 with an upper side 3 and a lower side 4 as shown in FIGS. The backing has side edges 5 at its periphery which join the upper side of the backing to the lower side. Furthermore, on the upper side of the backing is a coating 6 of abrasive that forms the surface layer and thus the final abrasive disc.

  In the production of the abrasive disc 1 according to the invention, the backing 2 is placed individually on the embossing piston 7 as shown in FIG. 7, and the backing of each abrasive disc is coated separately. In this way, each backing can be singly located in a pressing chamber formed by two embossing pistons 7 and 8 positioned facing each other. However, it is also possible to place the backing in one of several adjacent pressing chambers formed from two embossed pistons positioned generally opposite each other. It is also possible to place one or more linings adjacent to each other in a single pressing chamber without contact with each other, but again they can be coated individually. .

  Depending on the shape of the backing 2, in this embodiment the embossing piston 7, referred to as the upper embossing piston, is provided with a replaceable press head 9 for supporting the backing against the surface of the embossing piston. . If the bottom surface 4 of the backing is concave, for example, the embossing piston is therefore provided with a convex press head. Of course, it is also possible to provide the flat embossing piston with a lower mold of a suitable polymeric material to support the backing against the face of the embossing piston.

  When the backing 2 is properly positioned on the upper embossing piston 7, an abrasive coating 6 is applied to the upper side of the backing. Thereby, the structure of the surface layer of the abrasive coating is advantageously formed by bringing the embossing mold 10 arranged on the lower embossing piston 8 against the backing against the abrasive coating. In this way, the surface layer of the polishing disk is embossed with a desired pattern by pressing the embossed pistons positioned opposite to each other.

  In this way, the abrasive coating 6 can be applied directly to the upper side 3 of the backing 2, or alternatively, pressing the pistons together as described above and shown in FIGS. It is also possible to apply to the embossing mold 10 so as to be transferred to the backing.

  It is easy to use known vacuum casting techniques if the work is performed by a press having a small volume press chamber. A vacuum pump (not shown) is connected to the press via the mouthpiece 11, and then the atmospheric pressure in the pressing chamber can be significantly reduced. Thanks to this pressing and embossing technique, the embossing mold can be provided with a particularly fine particle structure that can be filled during embossing without any voids in the pattern.

  As shown in FIGS. 7 to 10, the embossing mold 10 can be advantageously formed by providing a collecting pocket 12 that surrounds the embossing mold 10. When the pistons are pressed against each other, a portion of the abrasive coating usually flows out. By allowing the collection pocket to surround the embossing mold, this extra material 13 is collected as shown in FIG. 10 so that the press and its peripheral devices are not soiled.

  After the mutual pressing of the pistons is complete, the abrasive coating 6 is cured and the mold that at least partially surrounds the finished abrasive disc 1 can then be removed.

  The application of the abrasive coating 6 can be carried out stepwise by supplying at least adhesive and sand alternately on the upper side of the backing. Alternatively, the abrasive coating can be dropped, sprayed, injection molded or injected onto the upper side 3 of the backing 2, for example using a slurry containing at least an abrasive and a binder. A screen print coating of the slurry is also possible, which results in a small spot of abrasive coating on the upper surface, ie, glue spots.

  The outer layer is formed in a generally spherical shape by coating the spherical upper surface 3 of the backing 2. In this regard, it can be noted that the sphere can of course be shown as both a convex and a concave surface. If a concave spherical surface is used, it is the inner side of the concave surface that is to be coated.

  In manufacturing, generally speaking, the spherical shape of the abrasive disc 1 may be any specific surface rounded regardless of whether it is a concave surface or a convex surface. In addition, additional bends 14 can be formed at the edges of the abrasive discs for discontinuous positioning.

  The distribution of the abrasive coating 6 forming the structure of the surface layer is in the form of an embossing mold 10 brought up to the lower embossing piston 8 in order to emboss the surface layer by pressing the embossing pistons against each other. Various forms are possible depending on the situation. The formation of the surface structure of this embossing mold can be advantageously provided by producing a special positive prototype embossing mold and then casting it in, for example, simple polymer molds. Thereafter, the embossing mold formed by the negative embossing mold of the releasing polymer is brought to the lower embossing piston, and embossing of the abrasive coating is performed. Such an embossing mold is simple and inexpensive to manufacture and can be used advantageously once. The release polymer material may be a normal polyolefin, such as polypropylene or polyethylene, but it is also possible to fuse the polymer material in order to further improve the peelability.

  Since the original embossing mold does not come into contact with the abrasive coating 6, its wear is minimal. The fact that there is almost no wear on the mold and the small size means that the structure can be made very fine. This gives a so-called fine replica. At the same time, this can make the pattern non-linear and non-interferent. Therefore, the composite structure of the abrasive coating is prevented from forming a linear trajectory that can leave a trace on the surface to be polished if the polishing disk moves in a one-dimensional direction.

  In screen-printed coatings, the abrasive coating is evenly distributed over the top surface, which is dispensed over the surface as a small point before pressing the pistons against each other, and then by a fine replica mold. It means that the desired distribution is easily produced in compression molding.

  At the same time, as the abrasive coating 6 is applied on the backing 2 as shown in FIGS. 8 to 10, the surface layer is also structured. In this way, two embossed pistons 7 and 8, that is, an upper embossed piston 7 on which the backing 2 is placed, and an embossed mold 10 disposed therein and having an embossed pattern are provided below the opposite sides. The side embossing piston 8 is aligned with each other. Thus, in the method according to the invention, none of the embossed pistons are brought into direct contact with the abrasive coating, and the pistons are partly protected by the embossing mold and partly by the backing. Thus, the coating is applied to the upper side 3 of the backing or the embossing mold.

  The lower embossing piston 8 having an embossing mold 10 with an embossed pattern can be advantageously formed of an elastic material with a convex end face. In this way, the embossing piston starts pressing from the center of the embossing mold as shown in FIG. Thereafter, as the embossed piston is increased in pressure and deformed as shown in FIG. 10, the pressing force gradually proceeds in a ring wave toward the periphery of the embossing mold. The upper embossing piston 7 or the surface of the press head 9 arranged therein is rigid and advantageously corresponds to the backing.

  The backing 2 and the embossing mold 10 arranged with respect to the upper surface 3 are, after the aforementioned mutual pressing, by the surrounding atmospheric pressure and the abrasive coating 6 applied between them before pressing. Held together. Thus, for example, it is easy to apply some known type of cure to the abrasive coating prior to pressing.

  Using a UV curable resin as a binder for the abrasive coating and forming both the backing support mold and the embossing mold 10 from a UV light transmissive polymer material, the abrasive disc 1 is conical. When conveyed through a cone of rays, the abrasive disc 1 can be cured easily and advantageously.

  The present invention also makes it possible to use electron beam cured resins since the radiation source may be relatively small if only one polishing disk 1 is exposed to the radiation at a time.

  The coating of the backing 2 of the abrasive disc 1 has been described above. In this regard, it may be mentioned that the backing can be produced by compression molding in a separate mold, in which case its upper side 3 can be coated when the backing is still in the mold. The backing may also be manufactured by stretch molding and then placed in a separate mold where its upper side is then coated. The stretch-formed backing can be cut from a strip of stretch-molded material, or it can be stretch-molded when a flat backing material is cut from the strip of material.

  The backing 2 of the abrasive disc 1 has, in one embodiment, a generally uniform thickness structure, so that the lower side 4 and the upper side 3 are generally parallel and have approximately equal bending radii. Yes. However, the backing has a shape where the lower side and the upper side have different bending radii, so that the lower side is, for example, generally flat, while the upper side can be spherical concave or convex. According to the method of the present invention, a surface layer in the form of an abrasive coating 6 which is generally in the form of a spherical segment can be provided on the upper side of the backing.

  Unlike today's paper-based abrasive discs, it is beneficial to produce a polymeric abrasive disc backing 2 according to the present invention.

  In order to simplify the use of the abrasive disc 1, a fixing element may be provided on the side edge 5 of the backing. These fixing elements are arranged to keep the finished polishing disk fixed like a lid when the polishing disk is placed on the fixing plate of the polishing head in use. The securing element may comprise an edge 14 drawn upward as shown in FIG. 5 or a hook drawn upward.

  The abrasive disc 1 can also be provided with holes for extracting dust or for supplying water. Furthermore, follower pins can be provided which cooperate with guide holes in the fixed plate. These tracking pins simplify the fixing and in some cases, for example when combined with the previously mentioned integral fixing element, eg self-adhesive green and Velcro fasteners (Velcro). Conventional fastening elements such as (registered trademark) fastening) are eliminated.

  It will be appreciated that the abrasive disc 1 includes an automatic adhesive and Velcro fastener on the lower side 4 of the backing 2 in order to secure the abrasive disc to a stationary plate on the abrasive head of the abrasive tool. Such a known fixing element may be provided.

  The above description and the associated drawings are only intended to illustrate the solution according to the invention for the structure of an abrasive disc. Therefore, the method according to the present invention is not limited to the embodiments described above or the embodiments described in the claims, but a number of modifications and alternative embodiments are possible within the scope of the concepts described in the claims. Is possible.

A top view of an abrasive disc is shown. A side view of an abrasive disc is shown. Fig. 3 shows a partial cross section of the abrasive disc shown in Fig. 2; An alternative embodiment of an abrasive disc viewed from one side is shown. 5 shows a partial cross section of the abrasive disc shown in FIG. Figure 3 shows a cross section of a second alternative embodiment of the abrasive disc as viewed from one side. 2 shows a partial cross section of a press for producing an abrasive disc according to the invention, with the press open for feeding. 8. A press according to claim 7 in which the embossing pistons of the press are locked together. The press according to claim 7 in a state where the pressing of the mutual press has started. The press according to claim 7 in a state where the mutual pressing is completed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polishing disk 2 Backing 3 Upper side of backing 4 Lower side of backing 5 Side edge of backing
6 Abrasive coating 7 Upper embossing piston 8 Lower embossing piston
9 Press head 10 Embossing mold 11 Mouthpiece 12 Collection pocket 13 Coating material 14 Fixing element

Claims (20)

A method of making a flexible abrasive disc (1) using an embossing mold that embosses a particular abrasive pattern of the disc on the flexible abrasive disc (1), the abrasive disc comprising an upper (3) In a method of making a flexible abrasive disc (1) with a backing (2) comprising a lower side (4) and a periphery,
a) An abrasive coating (6) is provided on the upper side (3) of the backing to form a surface layer, the abrasive forming a structured coating of the individual discs;
b) applying the abrasive coating to the upper side (3) of the backing (2);
c) placing the backing (2) for the abrasive disc (1) in a press facing the embossed piston (8);
d) A disposable embossing mold (10) made of a polymer material is placed on the embossing piston (8),
e) A pattern is formed on the upper side (3) of the abrasive disc (1) by facing the embossing piston (8) against the backing (2), whereby the abrasive coating is applied to the embossing mold (10). ) To the upper side of the backing or to the abrasive coating is embossed on the abrasive disc (1),
f) Curing the abrasive coating (6) on the abrasive disc (1) while leaving the embossing mold (10) in contact with the abrasive disc (1)
g) removing the disposable embossing mold (10) from the finished polishing disc (1);
A method of making a flexible abrasive disc.   2. Method according to claim 1, characterized in that the backing (2) is arranged on a piston (7).   2. A method according to claim 1, characterized in that a pressing chamber is formed over the backing (2) to be coated, the pressing chamber being evacuated so as to form a vacuum during the formation of the coating.   The method according to claim 1, characterized in that the backing (2) and the embossing mold (10) are shaped to have a generally spherical upper side.   5. A method according to claim 4, characterized in that the backing (2) is flat and has a substantially uniform thickness.   The method of claim 5, wherein the flat backing material is stretchable.   The abrasive coating (6) is applied stepwise by applying at least a binder and an abrasive to the upper side (3) of the backing (2) to form the surface layer. The method of claim 1, wherein:   The abrasive coating (6) is applied to the upper side (3) of the backing (2) in the form of a slurry containing at least an adhesive and a binder to form the surface layer. The method of claim 1.   An abrasive coating (6) applied to the upper surface when the backing (2) and the embossing mold (10) brought against the surface layer are pressed together and then pressed together. Are held together by which the abrasive coating is cured after the backing with the abrasive coating applied to the upper side is removed from the pressing chamber formed by the embossing pistons (7, 8). The method of claim 1, wherein:   The method according to claim 1, characterized in that the backing (2) is produced by injection molding in a separate mold.   2. Method according to claim 1, characterized in that the backing (2) is produced by stretch molding and then placed on a press piston, on which the upper side (3) is then coated.   12. Method according to claim 11, characterized in that the backing (2) is cut from a strip of stretch-formed material.   12. Method according to claim 11, characterized in that the backing (2) is stretch-formed when cut from a material strip.   The method according to claim 1, characterized in that the embossing mold (10) is formed of a polymeric material to constitute a disposable element.   The perimeter is pulled upward to form a lid-like edge on the disc (1), the lid comprising at least one intersection between surfaces having a diameter smaller than the largest diameter of the disc, The method according to claim 1, further comprising: forming a fixed surface of the disk to a disk support on the drive machine.   The method according to claim 15, wherein the lid is discontinuous and formed in a hook shape.   The method of claim 1, further comprising a pocket surrounding the embossing mold to collect overflowing abrasive coating. A flexible abrasive disc (1) comprising a backing (2) with an upper side (3), a lower side (4) and a perimeter, said upper side (3) comprising a structured coating An abrasive coating (6) to form a surface layer
The structured coating of the upper (3) surface layer is embossed and cured against a disposable embossing mold for the disc, which molds the disc with a molded coating pattern specific to that disc. A flexible abrasive disc (1) characterized in that it is fed.   19. A flexible abrasive disc (1) according to claim 18, characterized in that the backing (2) has a generally spherical upper side (3).   20. A flexible abrasive disc (1) according to claim 18 or 19, characterized in that the backing (2) is substantially flat and of approximately equal thickness.

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